1. Field of the Invention
The invention relates to a roll-up device for a safety belt with a provision for blocking the belt shaft in case of danger. The belt shaft is blocked by locking pawl means with locking teeth and a locking pawl which is operable by an automatically triggered release mechanism over a control element when the permissible acceleration or deceleration of the vehicle is exceeded.
2. Description of the Prior Art
In known roll-up devices for safety belts of the above-mentioned type (U.S. Pat. No. 3,901,459) a roll-up spring is arranged on one side of the belt shaft while the opposite end of the shaft is provided with locking pawl means and also with a release mechanism. In case of danger, i.e. when an acceleration or deceleration exceeding a permissible level occurs, the release mechanism which, for example, consists of an inertial mass, acts upon a control disc and the control disc effects blocking of the belt shaft by means of the locking pawl. Therein, the locking pawl and the locking teeth which are arranged in the same plane as the locking pawl, are disposed along the side plates of the U-shaped basic frame whereby the element with the locking teeth or the locking pawl are connected to the corresponding side plate through connecting pins or the like. This results, particularly when the locking elements are arranged on both sides of the basic frame, in a construction of relative great width. Therefore the connecting parts between the side plates and the locking teeth, or the locking pawl, must be made very stable or strong and therefore expensive, in order to withstand the extremely high pull forces at the safety belt and thereby at the belt shaft when it is blocked, and also to withstand the shearing forces associated therewith.